Defining the Relationship between Pocket and Breast Implant Surface Area as the Basis for a New Classification System for Capsular Contracture

BACKGROUNDThe precise cause of and treatment for capsular contracture remains uncertain, at least partially because there is no reliable quantitative measurement tool. To address this, it is postulated that the surface area of an implant as defined by the surrounding pocket may provide a quantifiable variable that can be measured to evaluate the degree of capsular contracture. METHODSA bench model for capsular contracture was developed. The surface area of a series of spherical test objects and noncontracted and contracted breast implants was measured using a wax-coating technique and three-dimensional reconstructions created from computed tomographic scan images. RESULTSComparison of the mathematically calculated surface areas to the wax and computed tomographic scan results for spheres of known dimension provided nearly identical values, documenting the accuracy of the two experimental methods. Comparison of the surface area measurements between the test groups showed that the average decrease in surface area for all implants was 20 percent, ranging from a high of 30.9 percent for a low-profile implant to a low of 14.1 percent for a high-profile implant. The anatomically shaped devices demonstrated nearly uniform degrees of surface area change over three different heights with volume and projection held relatively constant. CONCLUSIONSThe described bench model provides a useful tool for the study of capsular contracture. Surface area is a descriptive variable that can assess the degree of capsular contracture that is present. A classification system based on surface area is presented. CLINICAL QUESTION/LEVEL OF EVIDENCETherapeutic, V.